Hi,
I'm Horea from Romania.
I run BOINC on the local machine (i3-390M, 310M) and Azure (1CPU at 1.5 GFlops, 768 MB RAM).
Yesterday 8.julie.2012, I was looking silicates in the visible universe.
I mean, I searched the net visible universe map and I started looking for information about the map extremes in my search of humanoids based on silicon.
I had only negative results yet, but hope I succeed with your help.

So far we have found no evidence of life at any level using silicon instead of carbon for it's basic structure. I would think that if silicon is a viable alternative for life's basic building block evidence could be found here on earth since there is so much silicon available.

I didn't study very much biology in school but I do recall learning that the properties of carbon alone make it suitable as the basic element of life. No other element is capable of making the necessary chemical bonds and the transport of energy that is necessary to support life.

Now if you want to count super intelligent computers as a life form then you still have to consider who made them initially.
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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

AS a carbon based life form, we breathe and exhale Carbon Dioxide. A Silicon based life form would exhale Silicon Dioxide which is basically sand. So it would seem that a silicon based life form would be totally different from us .....

As us, the human race, has just found out, Silicon is an excellent substance for recording digital information on. We use it for our CD's because its easy to manipulate the atomic structure of silicon. And for electronics applications.

But silicon has extremely limited uses in biology. Even if our very best doctors, biologists and geneticists all sat down together and tried to invent a new genetic code based on silicon to create living things, it would be almost impossible. Silicon "sticks" very easily to oxygen in nature, we find it as Silicone dioxide, or Quartz. And because this silicon dioxide bond is so strong, it would make it near impossible to design any type of reproducing life with it.

Silicon is very good for building machines. But very bad for building living things that need to reproduce.

Perhaps a robot with a silicon Brain ( hugely fast mini-super computer) could behave as if human and also be capable of building others of his kind out of silicon and steel with the knowledge stored in his brain. Would this be a silicon-based life form. Definitition of life is now called into question.

At what point do you say he is an intelligent life form. This may revive the argument over whether or not machines can think. I think we would agree they can act intelligent in familiar circumstances and perhaps can exhibit adaptive behavior right now.

Daddio,
I think the more we learn about how "living things" work, at a molecular level, we will defiantly change our definition of what a "living thing" actually is.

Lets take a simple toy robot you buy for $20 in a children's toy shop. You put batteries in the robot, you switch on the robot, and it walks around the room and bumps into things. Maybe its an advanced programmable robot, so when its batteries run low, it looks for a wall socket to plug itself in to charge its batteries.

So is the toy robot a living thing? It does lots of things that a simple creature does? It walks around, it could make noises, and it looks for "food" in the form of an electric power point when its batteries are low. So for all intensive purposes, it might as well be classed as a living thing. The only real or apparent difference between it and an Ant or a Spider or a Beetle, is that it can't reproduce. And to someone who does not understand how electronics works, it might as well be a living thing.

Lets pretend for a moment that that toy robot could reproduce and create a new robot. And that new child robot could, in turn, reproduce again. Then it would continue on indefinitely. The truth is, its would be a living thing if it could keep reproducing.

On other dual star systems which accounts majority in the galaxy there might be little bit different natural forces can affect to bio materials chemical compositions process differently because the Earth's star is single star possibly certain forces affect differently on bio-chemical construction process over the millions of years.
____________
Mandtugai!

Plus it is kind of naive that assuming other stars must shed similar hydrogen based dust particles as our star. Because many different stars might shed different hydrogen compositions over the billion years hence could cause very different bio chemistry construction base for their local nature build up on a given planet.

It is already known that in different star cluster zones there are little bit different range of natural forces exist. In our case it is the carbon happen to have dominantly playing condition so this nature is created over 1 billion years of planetary bio lab condition.

Each day there is 100 000 tons of cosmic dust rains down to this planet so every lung based animals and breathing plants probably took daily cosmic fertilization dosage over the last billion years or the star shed materials.
____________
Mandtugai!

why carbon?
- we only know life-forms based on carbon
- carbon can create single-, double-,triple-bonds. (even with other carbon atoms)
- there can be hydrophilic and hydrophobic regions (- amphiphilic molecules- these molecules are very important for life in liquid solutin (h2o)- biomembrane- lipid-bilayer)
- alkanes, alkene, alkyne... long chains
- carbon compounds can create cycles, even heterocycles (with N eg.-> DNA, RNA, important for carrying the genetic information. maybe this information can be also saved on an aperiodic crystal..)

Plus it is kind of naive that assuming other stars must shed similar hydrogen based dust particles as our star. Because many different stars might shed different hydrogen compositions over the billion years hence could cause very different bio chemistry construction base for their local nature build up on a given planet.

It is already known that in different star cluster zones there are little bit different range of natural forces exist. In our case it is the carbon happen to have dominantly playing condition so this nature is created over 1 billion years of planetary bio lab condition.

Each day there is 100 000 tons of cosmic dust rains down to this planet so every lung based animals and breathing plants probably took daily cosmic fertilization dosage over the last billion years or the star shed materials.

Actually earth's magnetosphere prevents most of the cosmic dust and harmful radiation from entering the atmosphere and reaching the ground. The rest of what enters the atmosphere is not known to have any effect on our DNA or any other part of our biology.
____________
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

Plus it is kind of naive that assuming other stars must shed similar hydrogen based dust particles as our star. Because many different stars might shed different hydrogen compositions over the billion years hence could cause very different bio chemistry construction base for their local nature build up on a given planet.

It is already known that in different star cluster zones there are little bit different range of natural forces exist. In our case it is the carbon happen to have dominantly playing condition so this nature is created over 1 billion years of planetary bio lab condition.

Each day there is 100 000 tons of cosmic dust rains down to this planet so every lung based animals and breathing plants probably took daily cosmic fertilization dosage over the last billion years or the star shed materials.

Actually earth's magnetosphere prevents most of the cosmic dust and harmful radiation from entering the atmosphere and reaching the ground. The rest of what enters the atmosphere is not known to have any effect on our DNA or any other part of our biology.

Because that entering dust was coming from space at least for 4 billion years which in last 1 billion years the earth's live nature bio-chemical construction process took place meaning we are made of that dust which every lung based beings breathed that throughout their evolution period.

Maybe that is 100 000 tons per year not per day but still huge material come from space into earth nature.
____________
Mandtugai!